Guerrero is currently serving an eight-match ban for the unprovoked lunge from behind on Ulreich as the keeper was shepherding the ball out of play by the corner flag. The Peruvian forward was shown a straight red card.
Hamburg were three goals down in the home clash on March 3 at the time, and went on the lose 4-0.
The city's chief prosecutor, Willhelm Moellers, revealed that several criminal complaints have been made to the authorities, and the case is being investigated.
It is not the first time Guerrero, who has six goals in 21 Bundesliga appearances this season, has been in serious trouble with the German federation. In 2010 he was fined around £85,000 for throwing a bottle at a fan.